New tunable copper cavity could detect dark matter particles

Italian researchers have developed a novel tunable copper microwave cavity system to search for axions—hypothetical particles considered prime dark matter candidates—at higher frequencies than previously explored. Using two specialized haloscopes at the Laboratori Nazionali di Legnaro and Laboratori Nazionali di Frascati, the team scanned a frequency range centered around 10.2 GHz, corresponding to axion masses above 40 microelectronvolts (μeV). This mass region is of particular interest due to recent theoretical predictions suggesting axions here could account for the universe’s missing mass. The apparatus’s tunability, achieved by adjusting the cavity aperture, enables uniform sensitivity across a broad frequency range, allowing systematic scanning for axion signals. The detection method relies on axion-photon coupling theory, where axions in a strong magnetic field convert into detectable photons at specific frequencies. The copper cavity immersed in the magnetic field, coupled with a quantum-limited amplifier and antenna, is designed to isolate the extremely